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"ro ALL wnoii'rj MAY GONCERN:

W. P. W llNTlV ORTH, O F `l) ETRO IT, MICHIGAN. Letters Patent No. 66,059, (lated ffmc 25, 1867.

I IMPROVMENT IN DOOR-LOCKS.

Be it known thatl, W'. P. WENTwOiTzI, ot' Detroit, in the county of lVayne, and. State of Michigan,have invented :i new and improved Loek; and I do hereby declare tha-t the following Iis a full, clear, and exact description thereof, reference being had to the accompanying drawings, forming alpartjof this-specification, in

whichp l Figure 1 is a pcrspectiveview of `my inventionwith a portion ,ofi the slotted bolt removed in order to show the situation of the pawls inserted in the slot.

Figure 2 is the bol't separated from `the Vlock-case and emptied of thcpawls.

Figure 3 is one of the pawls, all of which arencarly uniformin outline.4

Figure 4 is the keywhich operates both the bolt`and the pawls. i

This invention consists in providing thc bolt with a slot forthe purpose of inserting pawls whichwill exactly slide between two posts placed upon either side of `the bolt when acted upon by a key peculiarly constructed for that purpose; but if acted upon bya key in the least respect dilierent from the required form,

some of them will catchyupon one `post or the other, thereby rendering itimpossibl'e to Spring thc bolt.

A, fig. 1 and tig. 2, is the bolt, and B is the slot. M Marc recesses in the shell ofthe slot, against the sides of which recesses` the twol ointsI I of the kcrlio'. 4 ress in turninythereb movin the bolt back and forth.

. P .fr D :P ,n y g J J are bars firmly attachedto each lower edgcof vthc slot to prevent the pawls O O O O O from `sliding down and outof the bolt. F F are Springs' attached to the pawls, and operating against the ftop of the lock-case lto keep th'e pawls in the required positionwhe-n not ac ted upon `bythe key. The pawls O O O O O correspond in length with the slot B, and move smoothly up and down inV the slot B, the width of the `fron-t end of each pawl O, including the catchesP and L, exactly corresponding with the width of the bolt. Theposts D and E are placed so that the bolt will exactly pass smoothly and evenly between them, and when the pawlsV O are lifted in the required manner they do not in the least hinder the free movement of the bolt. When the bolt is sprung forw'ard, as in `iig. 1, thc lower edges of the pawls O present a perfectly even surface between the bars J, that is, where thefkey` strikes them in turning,w,hilcthe edges of the lower projections or catches F otthe pawls are quite uneven, no two of them being of equal length. The distance between the lower edge of thecatch l and the upper edgc'of the catch Lof each `of the pawls being exactly equal, also exactly equal to the width ofthe bolt, it is necessary to use a key provided with notches, exactly fitting the different lengths of the catches, in such a. manner that it will raise the lower edge of earch ot' the catches P to an exact' level with the lower edge of the bolt atone and the same time, else nothing is accomplished toward opening th lock, for the least variation i from the` exact required `form of key will certainly raise some of the pawls too high or not high enough, conv sequently some ofthe catches will hold fast against one post or the other. The recesses M in the bolt are so shaped that the key does not strikethem until the pawls are allv lifted to an exact level-with `the bolt. The pawls O are of di'erent thicknesses, consequently the notches inthe key must correspond to the dilerent thicknesses, as

.well as to the dilerent lengths ot' the catches, orthc key is useless. The key-post H is not necessarilyapart of the lock, but it is necessary to my model tosteady` my key when the cover of theicaseis removed to witness the operatiolrof the lock. i i

In `door-locks it is necessary that the two halves of the numbc'r of pawls (that is from the centre oi' the slot to eachsideishould correspond, both inrgfflh and thickness, in order that the key may be used from cach side of thclock; `but for safe or other locks which require to lock only frornione side, no uniformity is necessary in the arrangement of the pawls. It is only necessary that the key exactly lits them. The number of i pawls may be increased or diminished` at pleasure, a great number requiring a greater thickness'of bolt. By varying `the number of pawls a greater number of' changes may be effected. By varying the thickness of the v pawls thc number of changes `may be doubled; 4and. by varying `the relative position of the pawls of different thicknesses the number of changes may be trebled. Changes may also be made by varying the distance of the key-hole from thebolt, so that hundreds of locks may be made, each of which will obstinatelyrefnse to yield save toits own identical key. The peculiar construction of the lock renders it obvious that is impossible for `anyperson to make a key which will unlock it unless he has the inside of the lock to make it by,`and it is also plain that no waximpression `can bclnkcn, for if the wax is firm enough io lift one pawl it must lift them all, l and no impression is made, for the edges present an even surface where tlickcy strikes them.

What Iclaim as new, and desire to secure by Letters Patent, is` The slot Bin the bolt A, in combination with the enclosed tumblers or pawls`0, operating as set orth.

W. P. WENTWORTH.

l WVitncsses: .l y

SIDNEY D.` Mattan, 1 Lnvx L. Banners. 

